Virgin Atlantic and British Airways are supporting the legal challenge to force the Government to reveal how it categorises countries in its traffic light system.
Court papers filed on Thursday name the two airlines as interested parties alongside Ryanair in a Judicial Review, the Telegraph reports.
Manchester Airports Group (MAG) is leading the challenge, with backing by Ryanair.
The court papers name Secretary of State for Health Matt Hancock and Secretary of State for Transport Grant Shapps as defendants.
Documents say it’s impossible for MAG or or any other travel business, to ‘make meaningful representations, to plan, or to scrutinise the legality of the decisions’.
The airlines say the Government has a duty to clearly explain how it makes decisions on categorising countries, and to publish the supporting data, given the ‘dramatic’ impact these decisions have on aviation businesses.
MAG CEO Charlie Cornish said: “Recent developments suggest that the Government is now unwilling to open up international travel by putting low risk countries on the green list.
“For most countries, the traffic light seems to be stuck on amber for no obvious reason, despite having prevalence rates much lower than the UK.
“The Government is not being open and we simply cannot understand how it is making decisions that are fundamental to our ability to plan, and to giving customers the confidence to book travel ahead.
“These issues must be resolved urgently – and ahead of the review point later this month – to allow everyone to understand how the system operates, and to create the opportunity for international travel to resume to the fullest extent possible over the summer.”
The Judicial Review has been prompted by the lack of transparency in how the Government made decisions in its first review of the traffic light lists on 3 June.
In a Statement of Facts and Grounds document lodged with the Court, the parties challenge the Government’s lack of transparency, particularly around the lack of clear reasoning given for moving Portugal from the green list to the amber list and its decision not to move any amber list countries to the green list.